Push to test pilot light



April 11, 1961 P. F. WHITE 2,979,593

PUSH To TEsT PILOT LIGHT 2 Sheets-Sheet 1 Filed Oct. 14, 1958 wm. 8 y /93/ ummm im 0 l i mL i; i5@ 35 I /f Il 1/ 7/ i 5 l; 1 J i 4 77 7 /T'ITJTI 65 34 F76 7 46 INVENTQR. j Pau! F Wfl/@ TEW M mi @7' April l1, 1961 P.F. wHxTE PUSH TO TEST PILOT LIGHT 2 Sheets-Sheet 2 Filed Oct. 14, 1958INVENTOR. Paul F Wfl/f6 lfinitrd,States.,f12F96@'0w i@ 2,979,593 u u i lPUSH To TEST PILOT .LIGHT Paul F. White, Glen Ellyn, Ill.,-assignor toFurnas Electric Company, Batavia, Ill., a corporation of Delaware Filedoef. 14, 195s, ser. Np. 767,193 4 claims. (cl. 290'1s9) The inventionrelates to electric switch structure and has reference in particular toa push to test pilot light of the type having a translucent push buttonandiwhich is illuminated when the enclosed bulb is energized inV -eitherof the two operative positions of the push button.

In switch structure of the character described the housing of the devicecontains a transformer and a plurality of fixed contacts are provided inassociated relation with movable contact bars. The movable bars areactuated by movement of the push button to connect the electric bulbacross respective circuitsras thefbars are caused to engage vwithcertain of the fixed contacts. Accordingly the device can -be employedfor testing the main circuit to an electric motor or the like in theevent a failure is indicated in the supply of current toA the' motor bythe auxiliary or control circuit. The invention therefore has for itsprimary object to providesuch a push to test pilot light of improveddesign, whereinthe various parts will be comp-actly arranged in theswitchehousing although capable of etiicient operation over long periodsof time without requiring any attention on the part of theV operator. v

Another object of the invention is to provide a push to test pilot lightwhich will incorporate a cover plate having a snap-on attachment to oneof the housing members so that the parts can be readily assembled ordisassembled andwhich when assembled will comprise a v unitary part ofthe complete switch device. Y

Another object is to provide apilot light as described which willincorporate a snap-on cover platefor one of the two housings of thedevice, the said housing con- 2,979,593 Patented Apr. 11,1961

' manner of attaching the snap-on cover;

taining the transformer and the spring-energized pusher c v member forthe pushv button.

A further object is to provide a pilot light of the character describedwhich will incorporate a snap-on cover plate for the housing containingthe transformer,

and wherein the cover plate providesa support for the light bulb, thesaid plate having the socket for the bulb iixedly secured thereto. Y

With these and various other objects in view, the invention may consistof certain novel features of construction and operation, as will be morefully described and particularly pointed out in the specification,drawings and claims appended thereto.

In the drawings which illustrate an embodiment of the invention andwherein like reference characters are used to designate like partsfFigure l is an elevational view of a push to test pilot switch, the sameembodying the improvements of the present invention;

Figure 2 is an exploded view of the switch of Figure l showing thevarious parts thereof in their relation -to one another `when assembled;

Figure 3 is an elevational view on an enlarged scale of the cover sideof the transformer housing of the switch structure showing the same withthe cover removed;

Figure 4 is a side elevational view of the transformer Figure 5 is afragmentary, vertical,` sectional view on the same enlarged scale `asFigure 3 ,andwhich illustrates the structural details of the operatingparts of the present switch;

Figure 6 is an elevational View ofthe cover side of the transformerhousing similar to VFigure 3 'but lwith, the parts being drawn onthesame scale as used forpFigures Yl Aand 2, and which shows the completeswitch in assembled relation; Y Y l Figure 7 is a front elevational',viewAof the plunger housing for vthe switch with theplunger're'taining plate removed; and

Figure 8 is an enlarged view `of the rear side of the4 plunger ion theenlarged scale lof Figure 5. ,l

, The push to test pilot-light as shown in the drawings comprises ingenerale, unitary base -10y which is provided with an upstandingcylindrical portion 11 threaded exteriorly at 12 for-a partof itsheight. The base 10 is formed with a central interior bore 13 and thesaid base is further characterized by an intermediate inwardlydirectedange 14l and an outwardly directed bottom flange Y15.V u Thepush button gener-ally indicated by numeral 18, and which is associatedwith the base 10, includes the adapter 19 and the lens 20. Whereas thebase and adapter may be formed of anyl suitable material such as metal,plastic or the like, -the lens 20- is formed of translucent material sothat the light from the bulb within the samewill be visible to theoperator. Thelens 20'is provided with a reduced portion at its base,which `portion is threaded fas at 21.,v The adapter 19'is also locatedVwithin the bore 13Wof-the base 10 andin the position as shown insaidfigures,y the reduced 'end 220i the adapteris located within the openingformed by the flange 14. A guide washer 27 is located below ange 1'4 andsaid washer additionally has contact with the bottom surfacevof theadapter.` TheV distortable sealing ring 28 hasl location within groove23 and `said ring completes the mounting ofthe push button within" thebase in Va manner wherein the button may be moved axially within thebore 13' ofthe said base. Should it be desired to'A mount the base andassociated switch structure on a mounting panel, the same can be readilysecured `to the panel, as shown in Figure 6, by employing the mountingwasher 30 and locking ring 31, said ring being interiorly threaded at 32for threaded engagement with the threads 12 located on the cylindricalportion of the base.

The switch structure for the present device is contained within av pairof housings ,-34 and 35, the former housing containing a plunger andswitch contacts, whereas the latter housing contains a transformer and apusher member. More particularly, housing` 35 is provided with adisposed at right angles to the said extensions. When the pusher plateis associated with the housing the base portion 44 is located underthe'intermediate partition wall 39 and the parts are normally maintainedin contact by the coil spring 45 contined'between the bottom wall 46 ofthe housing and the said base portion 44. Asa result of this structurethe extensions 43 are maintained in projected position above the topwall 37 and the same have contact with push button 18 to resilientlymaintain the same in extended position. The pusher plate 42 is held inoperative association with the housing 35 byv means of the cover plategenerally indicated by numeral 48, see Figure 4. Both ends 49 and 50 ofthe cover plate are bent at right angles thereto and the top end 49 isprovided with the support flange 51, the same being formed by being cutout from the main body portion of the cover plate. In accordance withthe invention the support flange 51 supports the socket 52 and theelectric light bulb 53. The socket 52 is ixedly secured to the ange andthe same locates the bulb within the lens of the push button. In formingthe support flange 51 by cutting out some of the material from the bodyportion of the cover plate, opening 57 is formed in the cover plate andprovision is made for the extensions 43 of the push plate to extendthrough said opening.

An additional feature in connection with the cover plate 48 resides inthe snap-on attachment which the cover plate has with the housing 35.For this purpose the bottom wall 46 of the housing is formed with thelocking ledge 47 and the bottom end 50 is provided with the upwardlybent locking liange 54. Also the top end 49 is formed with a pair ofopenings such as 55 which are adapted to coact with the positioning pins56 projecting upwardly from the top wall 37 of the housing `35. Figure 4illustrates the manner of attaching the cover plate 48 to the housing,which requires that the openings 55 and positioning pin 56 be broughtinto coacting relation with each other as shown, and then the bottom end50 can be snapped under the bottom wall of the housing whereby thelocking ange 54 will interengage with the ledge v47 to releasably retainthe cover in place.

The base 10 and housing 35 are releasably/secured to each other by meansof the clamping screws such as 58, adapted to have location within ,thelongitudinally extending grooves 59. 'I'he base 10 on its undersurfaceis formed with recesses 60 for receiving the positioning pins 56 whichproperly locate'the base l10 with respect to the housing 35.The'threaded ends of the clamping screws 58 enter vthe opening 61 andupon tightening of the screws the base 10 is connected tothe housing35with the end 49 of the cover plate being clamped between the parts,thus preventing any displacement of the cover plate with the parts inassembled relation.

The housing 34 is provided with the longitudinally ex- -tending channel64 for receiving the plunger 65. A central cavity 66 is also formed inthe housing 34 and within said cavity the stationary iixed contacts andthe movable contact bars are located. Considering iirst the stationaryfixed contacts, it will be seen from Figures v and 7 that a pair ofupper contacts 67 are supported by said housing so as to extendforwardly toward the front of the housing, and in a similar manner apair of lower contacts-68 are supported bythe housing. The said contactsVextend through the plunger retaining plate 70 torproject beyond thesame and the said projectingends are provided with terminal screws 71for theupper pair of stationary contacts and terminal screws 72 for thebottom pair-ofstationary contacts. The movable contact bars 73 and 74extend transversely of the plunger 65, for which purpose the plunger isprovided with an intermediate transversely extending opening 75, Figures5 and 8. The movable contact bars 73 and 74 are held in spaced relationby the coil vspring 76. The plunger 65 is additionally-characterized bythe provision of a stop shoulder 77 which -is adapted to contact theledge'78 provided by the'housing to limit the upward movement of theplunger. Said plunger is resiliently biased upwardly to maintain thestop shoulder in contact with the ledge by means of the coil spring 80,whichy is conned between the bottom wall 81 provided by the housing 34and the ledge 82 of the plunger. With the plunger being resilientlybiased into its upward projecting position, it will be seen that itsupper end projects beyond the top Wall of the housing for contact withthe push button so that actuation of the push button in a downwarddirection will result in similar movement ybeing imparted to plunger 65.

When the housing 34 is assembled with the base 10, the positioning pinsv83 have location inthe openings 84 formed in the base and the parts arereleasably secured to each other by the clamping screws 85. Said screwsextend through the longitudinal grooves 86 formed in the housing 34 andtheir threaded ends enter the openings 87 for threaded connection withthe base.

AAs a result of the expandingaction exerted -by the coil springs 45 and80 the pusher plate 42 and the plunger 65 are resiliently held inextended positions. It accordingly follows that the push button, whichmaintains contact at its base end with the pusher plate and plunger, isalso located in projected position. In this projected position of theplunger 65 it will be seen that the movable contact bar 73 is inelectrical contact with the upper contacts 67. When the push button isdepressed both the plunger and the pusher plate are depressed to asimilar extent and this movement of the members acts to compress thecoil springs 45 and 80. Downward movement of the plunger 65 willseparate the movable Contact bar 73 from the upper contact A67 and willcause electrical vcontact to take place between movable contact bar 74and the `lower contact168. Upon release of the push button by theoperator the springs 45 and will effect return of the-pusher plate,plunger and also the push button to their normal projected positions.

The present structure is unique in that two housings are employed, onefor the transformer and which additionally supports the socket and bulb,and the other housing for the plunger and switch contacts. Although thehousingsare independent, it will be seen that when they are in assembledrelation with the base 10, the plunger supported by housing 34 and thepusher plate supported by housing 35 have operative and joint coactionwith the pushbutton. The cover plate performs a dual function in that itretains the pusher lplate in operative relation with respect to housing35 and also supports the socket and the light bulb. Additionally, thecover plate closes its side of the housing 34 and its attachment to thehousing is materially facilitated by the snap-on structure pro vided bythese parts.

The invention is not to be limited to or by details of construction ofthe particular embodiment thereof illustrated in the drawings, asvarious other forms of the device will of course be apparent to thoseskilled in the art without departing from the spirit of the invention orthe scope of the claims.

What is claimed is:

1. Electrical switch structure of the character described, thecombination with a'base member having a base flange and a centrallongitudinal bore, a hollow cylindrical push button located within thebore and adapted to reciprocate with respect to the base member7 ahousing secured to the base flange, said housing mounting a pusher plateand which normally projects above the connection of the housing with thebase ange to extend within the central bore for contact with the pushbutton, resilient means for yieldingly forcing/the pusher plate into aprojected position, a cover plate for the 'housing adapted to have asnap-on attachment to the housing, said .cover plate when in attachedrelation on the housing functioning to retain the pusher plate inoperative supported relation on the housing, and an electric light bulbsupported by the cover plate and positioned within the push button.

2. Electrical switch structure of the character described, thecombination with a base member having a base flange and a centrallongitudinal bore,V a hollow cylindrical push button located within thebore and adapted to reciprocate with respect to the base member, ahousing secured to the base ange, said housing mounting a pusher plateand which normally projects above the connection of the housing with thebase llange to extend within the central bore for contact with the pushbutton, resilient means confined between a wall of the housing andV thepusher plate for yieldingly forcing the pusher plate into a projectedposition, a cover plate for the housing and which provides a front wallfor the same, said cover plate having a releasable attachment to thehousing and when in attached relation functioning to retain the pusherplate in operative supported relation on the housing, a socket xed tothe cover plate, an electric light bulb adapted to be retained by thesocket and positioned within the push button, a second housing securedto the base ange, said second housing mounting a plunger also normallyprojecting above the connection of the housing with the base ange toextend into the central bore for contact with the push button, aplurality of stationary contacts supported by the last mentionedhousing, and contact bars carried by the plunger for coaction therewith.

3. Electrical switch structure of the character as delined by claim 2,additionally including resilient means within the second housing foryieldingly forcing the plunger into a projected position.

4. Electrical switch structure providing a push to test pilot light, incombination, a base member having a base flange and a centrallongitudinal bore, a hollow eylindrical push button located within theVbore and adapted to reciprocate with respect to the base member, ahousing secured to the base flange, said housing including side walls, arear wall and top and bottom walls, a cover plate for the housing andwhich provides the front wall thereof, means on the housing forreleasably attaching the cover plate to the same, a socket liXed to thecover plate to extend above the connection of the housing with the `baseflange and within the bore, a second housing secured References Cited inthe iile of this patent UNITED STATES PATENTS Hallerberg et al June 14,1955 Johnson et al. July 12, 1955

